Friday, July 23, 1999 Published at 11:29 GMT 12:29 UKSci/TechChemical trap for Asian beetleThe beetle prefers maple species of tree (USDA)US Government scientists have turned to chemistry to beat the Asian Longhorned Beetle.

The alien pest has already caused extensive damage to tree populations in the north east of the country. New York City alone has lost 3,000 trees to the creature in just two years.

Department of Agriculture researchers are attempting to make a "lure" based on two chemicals produced by males of the species. Scientists have copied the chemicals because they appear to be potent attractants for both sexes.

During promising lab tests in a wind tunnel, the two synthetic pheromones were the only substances, from either plants or insects, that interested the beetles enough to encourage them to fly toward the source.

Field tests in China are currently underway. If the attractant is effective and works at appropriate distances, baited traps can be used in the US to help flush out undetected beetle infestations and monitor high-risk areas, such as import warehouses and ports, for new introductions. The work of the government entomologists is now also the subject of a patent application.

'Roach Motel'

"Our goal is to eradicate this pest," said Agriculture Secretary Dan Glickman. "And this new lure could help us set up a Roach Motel with lifetime rooms set aside specifically for Asian Longhorned Beetles."

The pest is now considered a major economic threat in both the US and Europe. The beetles, originally from China, Korea and Japan, stow away in the wooden packing cases used to ship goods.

They bore finger-sized holes in trees to lay eggs. The larvae eat their way under the bark, eventually killing the trees. City and forest authorities have no choice but to fell infested wood.

The beetles prefer maple species of tree, including the box elder, Norway, red, silver, sugar and sycamore maples. This could spell disaster for New England, which is famed for its maples. A state like Vermont is 80% forest and almost every third tree is a maple.

He said that goods would be sent back to China if wooden crates were not certified as treated.

In the UK, legislation has been introduced to make it illegal for anyone to knowingly bring the creatures into the country. This unprecedented move followed about 20 reported sightings of the beetle or evidence of its presence in Britain.